Grantee Research Project Results
Distribution of Cs-137 in the Lena River Estuary-Laptev Sea System as Evidenced by Marine, Estuarine, and Lacustrine Sediments
EPA Grant Number: U915134Title: Distribution of Cs-137 in the Lena River Estuary-Laptev Sea System as Evidenced by Marine, Estuarine, and Lacustrine Sediments
Investigators: Pyrtle, Ashanti J.
Institution: Texas A & M University
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 1997 through January 1, 2000
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1997) RFA Text | Recipients Lists
Research Category: Fellowship - Oceanography , Academic Fellowships , Fellowship - Aquatic Ecology and Ecosystems
Objective:
The goal of this research project was to examine geochemical and physical processes that have led to the enrichment of 137Cs-137 in Lena River estuary sediments. Geochemical and physical factors examined in this investigation include mineralogy, sediment chemistry, particle transport mechanisms, and sea-ice related processes.
Approach:
Surface Cs-137 activity was determined for all samples. Chemical, mineralogical, and grain-size compositions were obtained for a subset of samples, in order to determine if the distribution pattern of Cs-137 was the result of geochemical factors influencing the adsorption/desorption process of Cs-137 onto the sediment particles. Cs-137 inventory values for several cores also were also obtained. By comparing the analytical results of the marine, estuarine, and lacustrine samples, conclusions were drawn concerning the distribution pattern and the source(s) of Cs-137 in this Arctic environment. Excess Pb-210 analysis was conducted on a subset of samples, allowing conclusions to be drawn concerning particle deposition and/or removal via riverine discharge and sea-ice related processes. The Cs-137 and excess Pb-210 activities were determined using a germanium well detector and a lithium-germanium planar detector, respectively. The chemical composition of a subset of samples was obtained using x-ray fluorescence and neutron activation techniques. The mineralogical and grain-size distributions were determined using x-ray diffraction and pipetting techniques, respectively. A mathematical model was used to determine particle mixing and burial rates.
Supplemental Keywords:
fellowship, Lena River Estuary, estuary sediments, marine, estuarine, lacustrine, sediment particles, particle deposition, sea-ice related processes, Arctic.Progress and Final Reports:
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.